Therapeutic modalities are physical agents used to reduce pain and swelling and to help restore range of motion, strength, and function following an injury. Two of the fundamental modalities used to treat injury are heat and cold. Both cold and heat therapy have been found to be clinically effective in accelerating the healing of damaged tissue. Particularly, cold therapy acts to retard metabolism within the tissue cells, whereas heat therapy accelerates cellular metabolism. Often, physicians and therapists prescribe use of both modes of therapy alternately. In this regard, both heat and cold therapy are of particular value because of their effect on the pain and inflammation that occur as a response to injury.
Thermal therapy is the treatment of diseases by raising the temperature of the tissue. The mechanisms by which this is accomplished are threefold, i.e. conduction, convection, and radiation. Conduction is direct contact, such as occurs with the application of a hot pack. In convection, a medium such as hot air or water is applied around the injured part, as in a whirlpool. In radiation, a source of warmth, such as a heat lamp, is used to heat the body part. Heat produces analgesia by diminishing the afferent pain impulses, causes vascular dilation that improves the blood supply, and increases the metabolic rate by speeding up the rate of enzymatic reactions. Heat also increases collagen extensibility, which improves overall flexibility and enhances motion. Finally, heat causes a decrease in muscle tone and muscle spasm. As such, localized heat therapy is of particular benefit with orthopedic conditions such as lower back pain, strains, acute injuries, chronic pain, muscle spasm, tendinitis, and arthritis. Heat therapy is also prescribed for skin trauma (bruises, contusions, abscesses, boils, burns) and other medical problems like infection, phlebitis, I.V. infiltration, and neuritis.
Cryotherapy is the use of cold to treat injury or disease. The consensus among medical professionals is that cold is a standard treatment for both immediate care and for rehabilitation following most soft-tissue injuries. Cold works by its effects on metabolism, circulation, inflammation, and edema. Because cold slows enzymatic function and, hence, metabolic reactions, any metabolic reaction association with inflammation is inhibited and its effects are mitigated. Cold also causes vasoconstriction which, though not preventing hemorrhage, prevents the extension of hematoma.
The application of cold also increases collagen stiffness, thereby decreasing the extensibility of tendons and ligaments, and delays, but does not eliminate, inflammation. Edema is reduced, usually as a result of the use of cold together with compression and elevation. In addition to decreasing the temperature of skin, subcutaneous tissue, muscles and joints, the application of cold relieves pain by slowing or blocking nerve impulses, and also decreases muscle spasm. With the decrease in pain and muscle spasm, early mobilization and exercise can be undertaken more comfortably. Typically, cold is applied by the use of ice massage or ice baths, as well as through the use of gel refrigerator chemical packs (which produce an endothermic reaction) and refrigerant compression machines.
Advantageously, cold applications used during rehabilitation allow immediate mobilization and make it easier for the patient to begin therapeutic exercise. Localized cold therapy is often used in the operating room, the recovery room, the intensive care unit, in physical therapy and in individual patient rooms. It is used effectively to treat surgical incisions, as well as wound and inflammation caused by traumatic injury. With regard to surgical applications, cold therapy is often prescribed in relation to orthopedic, neurologic/orthopedic, abdominal, oral, ufological and obstetrical/gynecological surgery. In most cases, cold therapy is applied immediately following the surgical procedure, directly to the wound site. This acts to reduce swelling and pain, while also reducing or eliminating the need for pain-killing medications.
For the specialty of hand surgery, cold therapy is also applied to the upper extremity before and during the procedure in conjunction with a tourniquet. This is done to extend the surgical period beyond the normal time limit by decreasing the adverse effects of tourniquet ischemia. Other conditions indicating the application of cold therapy include acute injuries, bruises/contusions, chronic pain, muscle spasm, strains, arthritis, cellulitis, lower back pain, sprain and alopecia. Both cold and heat therapy are also used extensively outside the hospital in physician's offices and out-patient clinics.
Due to the numerous advantages attendant to the use of cold and heat therapy for therapeutic applications, various prior art medical devices have been developed to facilitate such application. However, many of these prior art devices lack portability and are adapted for use solely in environments such as a hospital, a physician's office, or an out-patient clinic. Additionally, many of these devices and systems are difficult to use and expensive, thus making their use impractical by an untrained individual in an environment such as the home. The present invention addresses these shortcomings by providing an inexpensive, portable fluid therapy device for the application of heat or cold therapy to a desired region of the body which may be utilized in the home to facilitate desired therapeutic treatment.